L-jet on an MGB

[Edward Hernandez R]

"I had intentions of having port injection, but because of the siamese
 ports with non-symetrical intake stroke I decided to go the trottle
 body injection route.  This is undesirable, and not necessary if you 
have individual ports per cylinder."

Actually, there is nothing wrong with assymetrical intake ports for 
the DIYer. There are OEM applications with these kind of ports, and if
we can make it work to meet strict emissions and fuel economy 
standards, you can make it work for DIY. Just be careful which at port
you choose for injecting fuel.

"I was wondering, does anyone know of a function that roughly follows 
the V.E. vs. RPM of an engine.  Engine size, manifold pressure and 
intake temperature I'm sure affect V.E., but I'm just looking for a 
cheap estimate."

There is no cheap estimate or generic function. The variables you 
mention and many others preclude the use of generic functions. I'd 
have to agree with M Sargent on the use of commercial programs for 
your best/cheapest bet. They aren't perfect, but will do for DIY.